1. Field of the Invention
This invention relates to plastics boxes, and in particular to so-called "fish boxes" for use on board fishing boats at sea for receiving freshly caught fish. When the fishing boat returns to port the catch is handled by means of the fish boxes.
2. Prior Art
Plastics materials lend themselves to the production of boxes of various configurations by moulding. Numerous varieties of plastics boxes have been proposed for particular purposes. The desires of substantial structural strength on the one hand and lightness in weight and simplicity of construction on the other hand are frequently competitive. Heretofore, various designs of boxes for different purposes have arrived at different compromises between these two desires.
It has been proposed, for example, to shape plastics boxes, and in particular containers intended to be both stackable and nestable, with corrugated side and end walls so that the side and end walls have a somewhat wave-shaped contour in horizontal section. U.S. Pat. No. 3,052,373 of Frater (1962) and U.S. Pat. No. 3,270,913 of Bridenstine et al (1966) are typical of such prior containers. The principal purpose for the construction adopted was so that with two identical containers in the same orientation placed upon each other, the two containers would be nestable whereas reversing the relative orientation by 180.degree. causes the containers to be stackable rather than nestable.
The containers of Frater and of Bridenstine et al are primarily intended for the transport of relatively lightweight and easily damaged foodstuffs to retail outlets. It will be appreciated that fish boxes are utilised in very different circumstances and in very much more harsh environments. Fish boxes require substantial structural strength. The boxes must be capable of being placed alongside each other and of being stacked upon each other so that as much as possible of the interior of the hold of a fishing vessel may be utilised. Additionally, the boxes should also be capable of being readily cleaned, as for example by being flushed with water.
While attempts have been made to shape fish boxes also with corrugated side and end walls rather in the manner of U.S. Pat. Nos. 3,052,373 and 3,270,913, the resultant constructions have not been sufficiently acceptable. The corrugated construction provides a more intimate contact between adjacent boxes in the hold of a fishing vessel since the corrugation projection of the side wall of one box may be inserted into the corresponding corrugation trough in the side wall of an adjacent box. Additionally, this construction achieved a certain improvement in resistance of the box to sudden impacts, as frequently occur while in use in a fishing hold or in removing the catch to the quayside. However, it was found that the corrugated surfaces which were employed, having comparatively narrow flutes, tended to damage the fish in the boxes. The design was accordingly rejected.
With other previously proposed fish boxes, the wall thickness, and thus the weight of the box, needed to be substantial unless special measures were taken to reinforce the walls, for example by providing them with bracing elements which themselves required additional plastics material and also resulted in abrupt changes in the surface making it difficult to keep the boxes clean.
A common resort to provide structural strength to the boxes, has been the provision of reinforced uprights in the edges between the side and end walls. While it was found that such reinforced edge portions provided the structural strength if boxes were stacked one upon the other, the wall portions intermediate the edges did not possess adequate strength.
There is an evident need for an improved fish box achieving good strength/weight ratio without a need for corner reinforcements and which nevertheless enables easy cleaning and ready stacking.
An additional problem for prior designers of fish boxes has been the provision of an adequate hand grip. A common expedient has been to provide a through aperture in each end wall both for manual handling and for the insertion of machine elements in mechanical handling. This has frequently proved disadvantageous since, in order to preserve freshly caught fish at sea, it is a common practice to partially fill the box with fish and to place a layer of ice on top of the fish. With through hand holds, the ice is exposed to air and will melt readily at ambient temperatures above freezing.
The aforementioned problems and disadvantages inherent in the previously proposed fish boxes can be readily overcome by the use of preferred embodiments of fish boxes constructed in accordance with the present invention, as will become clear from the detailed description which follows.